1. Field of the Invention
The present invention relates to a dental hydraulic temporary sealing material composition used as a temporary sealing material in dental treatments.
2. Description of the Conventional Art
In dental treatments, temporary sealing for sealing a cavity for a fixed period of time has been performed for follow-up observation until a next visit to a dental clinic, prevention of food piece insertion and bacterial infection into a cavity until a dental crown product is produced after forming the cavity, prevention of leakage of a medicament filled in a cavity or a root canal, and the like. The dental temporary sealing material means a material used for such the temporary sealing.
As for the characteristics of the dental temporary sealing material, the material has a closely sealing effect, can resist occlusal pressure so as not to be broken, fallen, and deformed, is not harmful to hard tissue of a tooth and a pulp, can be easily operated to be filled and removed, and the like. The dental temporary sealing material can be roughly classified into three kinds, i.e., thermoplastic resins (a temporary stopping), dental cements (an eugenol cement, a non-eugenol cement, a zinc phosphate cement), and hydraulic temporary sealing materials.
Since the thermoplastic resin (temporary stopping) is formed in a rod shape or a pellet shape and supplied, the thermoplastic resin is used by being heated/softened and pressed to contact with the cavity. The thermoplastic resin has been widely used because filling and removing operations are easy. However, since the shrinkage of thermoplastic resin is large at a time of being cooled/cured, adhesiveness between the thermoplastic resin and a cavity is not enough, so that the thermoplastic resin does not have sufficient sealing property for the cavity. Further, since the thermoplastic resin needs heating/softening at a time of filling, flame and the like are certainly required when the thermoplastic resin is operated, so that the operation for the thermoplastic resin is complicated.
Further, the dental cements (an eugenol cement, a non-eugenol cement, and a zinc phosphate cement) are filled after being mixed powders and liquids to be a paste state. Since these dental cements become a set material with proper hardness in several minutes, these dental cements have excellent sealing property for the cavity, and may have effects of sedation, analgesia and antimicrobial activity. However, the mixing operation of powders and liquids is complicated and needs skillfulness. Further, there is a fault that a removing operation is difficult because the set material is comparatively hard. Furthermore, the eugenol cement has problems of a peculiar odor and stimulation to mucosal tissue.
The hydraulic temporary sealing material does not have adhesiveness with cavity, but when a putty-like paste is filled in the cavity, the paste reacts with water such as saliva in an oral cavity and is set. Therefore, the hydraulic temporary sealing material does not need mixing/heating, and has good operativity. Further, the hydraulic temporary sealing material has good sealing property because it expands at a time of setting (e.g., refer to Japanese Patent No. S38-2628). However, since the hydraulic temporary sealing material utilizes a setting mechanism due to the reaction of calcium sulfate in a composition with the water in the oral cavity, there are problems that a setting time is long and the initial setting time is particularly slow.